Process for obtaining rubber-containing or similar materials



Patented Feb. 17, 1925.

ERNEST HOPKINSON, OF NEW YORK, N. Y.

PROCESS FOR OBTAINING RUBBER-CONTAINING R SIMILAR MATERIALS.

Ho Drawing.

To all whom it may concern:

Be it known that I, ERNEST HOPKINBON, a citizen of the United States, residing at New York city, county of New York, and

State of New York, have invented certain new and useful Im rovements in Processes for Obtaining Robb lar Materials, of which thefollowing is 'a full, clear, and exact. description.

10,! This invention relates to processes for obtaining combinations of'fibrous or filamentary material and rubber, and to the products obtained thereb i The primary object 0% the invention is the direct utilization of rubber latex in the manufacture of products and materials,

articularl sheet material, containing firous or fi a entary elements. Another object of the invention is to obtain such roducts or materials by a simple and rapitfprocess, or processes. It also aims to provide superior products or materials by reason of the improved character of the rubber obtained directly from latex, and combined with,.or bindin the fibrous or filamentary material. Anot or object of the invention is to rovide a'process of admixin which shafi be continuous and in which t e fibers, or the like, are thoroughly incorporated U with the rubber latex without undesirable twisting or" gnarling thereof. A further ohject of the invention is to provide an admixture of rubber, .or the like, with filamentary or fibrous materials which, while possessing resiliency, shall possess a stiflness greater than of rubber as such, which shall possess improved resistance to tearing, and which is substantially homogeneous.

' With specific embodiments in mind. and

without intention to limit more than is required by the prior art, the briefly stated, consists in, mixing rubber-latex as such with, or applying it in a finely divided condition to, a mass of filamentary or fibrous materials, such as cotton, wood pulp, or other cellulose material, wool or other textile fibers orfilaments of these or various other materials.

The rubber latex which is to be combined with the fibers, may be employed in its natural condition, in which it ordinarily contains around 30% rubber, or in a m re widely. It may,

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invention,

Application filed September 25, 1918. Serial No. 326,276.

or less diluted or concentrated condition suited to the character of the fibers, or of the end product or material desired, whose physical characteristics, ofcourse, may vary v or may not, contains preservative, such as ammonia, or other a cut for preventing premature coagulation. uch an agent is ordinarily necessary for the preservation of the latex in transport rom the plantations, or when it must needs stand a long time before use. And it may, or may not, contain fillers, or other compounding ingredients and vulcanizing agents, as the products, or sheet material, may re uire.

Any vegetable, animal and miners fibers, alone or mixed together, and of short or long staple, such for instance as cotton, asbestos, wool, wood pulp, hemp and similar fibers, chemical paper pulp, straw pulp, and mechanical wood pulp, may be combined with the rubber-latex according to the invention, and formed into widely different products, or sheet materials. The processes may va in details to meet the re uirements 0 different fibers and to yiel the desired end product, and the invention, in its broadest aspects at least, is not intended to be limited to details peculiar to particular fibrous or filamentary, materials, and to particular end products or sheets.

By way of illustration, however, andwith the manufacture of sheet material from cotton fibers and rubber-latex in mind, the following processes are set forth.

Upon albelt, preferably of metal having a polished surface, an initial coating of rubher-latex combined with sulphur, or other vulcanizi ingredient, is placed, and upon it is fed. row a carder, a web of cotton which has been preferably reduced to extreme tenuousness by providing a draw ratio in the carder of a proximately 1:36, or the carder may be eliminated and instead the fibre scraped from the bat of the liclremin roll may be blown off by a blast of air delivered at any desired point on the periphery of the roll. This material may then be passed on to the belt. v

This web is fed on to the upper surface of the applied latex and duri or after said a plication is spra ed with atex provided W' lth sulphur or ot er vulcanizing agent or compound if desired. The traveling belt continually carries the admixture forward in sheet form, passing it through a heated chamber or across any desired heating area such as coils beneath the belt to a rollin -up device which may consist of a roll w ich strips the sheet of dry rubber and fiber from the belt, or the strip may be allowed to remain on the moving belt traveling again beneath the web delivery, receiving another layer of web which in turn receives a coating of latex. This procedure may be repeated until a plied material of desired thickness has been built up. The temperature of drying is approximately 210 F. and the speed of the admixed sheet described is adjusted so that drying may take place in any desired time preferably during one revolution of the belt where the material is allowed to build up on the belt. here a winding-up roll is used,the latter strips the sheet from the belt at the end of the process. Sheets as thin as .003" may be formed if desired. The plied sheets'may be fabricated to form tires, hose, etc., and vulcanization may then be carried out.

Instead of the application of latex to the fibrous material as indicated above, a proccss may be carried out as follows: A mass of cotton or other fibrous or filamentary material is introduced into a chamber and evacuated. Latex is then introduced in the chamber into contact with the cotton by which it is absorbed. The latex may contain sulphur or other vulcanizing ingredient or compounding materials if desired. When impregnation is complete, during which it has been found that the capillary tubes of the cotton fibres themselves are filled with latex, the material is dried and may be then vulcanized in any well-known manner. Prior to vulcanization, the material ma be shaped to the form of any desired artic e.

As an alternative methodfto those described above, the following procedure may be also carried out in efi'ectmg admixture of filaments of rubber or the like:

A thin web is prepared as described above by a carding machine and the fibres are evacuated by the application of vacuum to such web and are then run into a bath of latex being suitably supported in their travcl through such bath by a wire screen running over idler rolls immersed in the latex. After emerging from the latex the web may be led over suitable dryin rolls and wound up on receiving rolls in s cet form. They may thereafter be manipulated to fabricate various rubber articles as desired. It will be observed in this process that the fibres passing directly from the vacuum chamber into the bath are readily impregnated in the absence of air. If desired the vacuum chamber may be eliminated in this process and instead the web may be passed from the cards supported by a wire screen as before, through a series of squeeze rolls immersed in a bath of latex which serve to remove the air and thus to permit penetration of the fibre by the latex.

In each of the procedures just given vulcanizing agents may be applied before or after fabrication and vulcanization accomplished. In general, these various procedures result in a compacting or matting of the fibers, the liquid content of the latex effecting this matting especially when pressure is applied to the latex-treated mass of fibers.

The material produced by the above process possesses among others the desired characteristics sought for in the objects of the invention mentioned above. In accordance with the content of rubber with respect to the cotton fibre or other filamentary or fibrous material employed, the resulting products will more or less nearly resemble rubber as such. It is found with increasing admixture of fibre that the stiffness of the resulting compound is increased while the resiliency is maintained and at the same time the resistance to tearing becomes greater. With the content of rubber equal approximately to six times that of the fibre present, a material is provided which in its physical properties resembles closely the rubberized cord material of cord tires. It has stiffness, resiliency and great resistance to abrasion, and upon examination of the material it is found that the fibres are substantially uniformly distributed throughout the mass of rubber.

The admixture of chemical paper pulp in rubber-eontaining latex or the like may be efi'ected as heretofore described in connection with cotton fibres or the latex may be mixed with a artially dried pulp and allowed to coagu ate either naturally or by the introduction of an artificial coagulant. The products obtained by such admixture include, among others, substantiall watcrproof pers and plastic compositions having mo dable properties, An increase of the rubber content will serve to provide pro ducts varying from such waterproof paper and their properties to those having molding properties more closely resembling those of rubber. Moldable compositions made from the admixture of paper pulp with latex upon vulcanization provide a material capable of being manufactured into various devices such as toilet articles, trunks, pottery substitutes such as cups and saucers, beer bottle caps, etc. It will be observed in this connection that in carrying out the invention herein set forth, the latex may be bleached by a suitable oxidizing agent such as sodium bisulphite to cause a whitening thereof.

Straw pulp or mechanical wood pulp may be employed in the manner recitedabove for chemical pulp, and thereby cardboard and similar materials may be fabricated. A waterproof and weatherproof coating may also be provided on hemp and similar fibers that are employed in the manufacture tionto the vulcani'zing process may be carried on. \Vhere vulcanizing agents are used, various types may be employed, such as sulphur, nitro organic compounds and the like, as well as materials includi'n sul hur, such as hydrogen sulphide, 31H? su phnr dioxide.

In the foregoing, it has been endeavored to illustrate with specific examples, the breadth and scope of the invention, which is intended to comprehend the application of rubber-latex in a natural or modified form to a wide variety of fibers, with or without compounding and vulcanizing ingredients. The rubber-latex may be applied in any manner suited to the requirements of the particular fibers and their condition or arrangement. And their vulcanization, if required or desired, may be carried on or efiected as convenient;

- As many apparently widely different embodiments of this invention may be made without departing from the spirit thereof, it will be understood that I do not intend to limit myself to the specific embodiment herein set forth except as indicated in the apIpIended claims.

aving thus described my invention, what I claim and desire to protect by Letters Patent is 1. A process for treating rubber-containing latex or similar material which oomprises, converting the latex into a finely divided condition brin 'ng the so-divide'd latex into contact wit a cellulose fibrous material and drying the mass.

2. A process for treating rubber-containing latex or similar material which comprises, spraying the latex upon a web of cotton and drying the mass.

3. A process for treating rubber-containing latex or similar material which comprises, spra ing the latex upon a continuous moving we of cotton and changing the fluid content of the mass.

4. A process for treating rubber-containing latex or similar material which comprises, converting the latex containing a vulcanizing agent into a finelg divided condition, combining the so divi ed latex with filamentary substances, drying the combined mass and subjecting the products so obtained to a vulcanizihg' action.

5. A process for treating rubber-containing latex or similar material which comprises, ously moving web of cotton, substantially completely dryin the latex so as to bond the mass of cotton bers together and form a sheet, manipulating the sheet material to form a tire carcass and vulcanizing'the carcass.

6. As a new product, an altered rubbercontaining latex or similar material which comprises a filamentary substance combined with finely divided comminuted latex.

7. As a new product, an altered rubbercontaining latex or similar material which comprises a filamentary substance combined with finely divided comminuted latex and a vulcanizing agent.

8. A process of ma sheeted fabric consisting in forming an initial coating of latex combined with sulphur on a moving metal belt, feeding a web of filamentary material to the surface of the ing the web with latex containing sulphur, drying and stripping off the sheet and vulcanizing it.

9. That method of manufacturing sheet material which consists in, arranging fibers to form a sheet of any desired length, continuously treating the sheet of fibers directly with rubber-containing latex, and drying the treated sheet of fibres to obtain a sheet material in which the bond between the fibers consists of solid constitucuts of latex.

10. That method of manufacturing sheet material which consists in, continuously collecting fibers in an unbroken layer to form a sheet of anydesired len h and thickness, matting the fibers toget er'with rubbercontaining latex while continuously moving the sheet thereof, and substantiall completely drying the mass and bonding the fibers together with the solid constituents of the latex. 11. That method of manufacturing sheet material which consists in, continuously collecting the fibers in an unbroken layer to form a sheet of any desired length and thickness, matting the fibers together with rubber-containing latex while continuously moving the sheet thereof, substantially completely drying the mass and bonding the fibers together with the solid constituents of the latex, and finally vulcanizing the bonded-together fibers to form a compact sheet material.

12. That method of manufacturing sheet material which consists in, continuously depositing a mass of cotton fibers on an endless moving belt, and successivel and simultaneously treating the supplie mass of fibers with rubber-containing latex and drying the spraying the latex upon a continulatex, spraycontinuously pre- 4 same whereby a sheet material of any desired thickness and substantially uniformly bonded together with dried latex may be obtained.

13. That method of menufacturing sheet material which consists in, continuously forming a web of fibrous material and rubher-latex of any desired length, Width and thickness, and drying the same so as to form a sheet bonded together with solid constitu- 10 outs of rubber-latex.

Signed at New York, N. Y. this 24th day of September, 1919.

' ERNEST HOPKINSON.

same whereby a sheet material of any deher-latex of an desired len th width an sired thickness and substantially uniformly thickness, and rying the Sar e sb as to forn i bonded together with dried latex may be oba sheet bonded together with solid constitu- 10 tamed. ents of rubber-latex.

13. :Ihat Inethod of manufacturing sheet Signed at New York, N. Y. this 24th day material WlllCll consists in, continuously of September, 1919. forming a web of fibrous material and rub- ERNEST HOPKINSON.

Certificate of Correction.

It is hereby certified that in Letters Patent No. 1,526,984, granted February 17, 1925, upon the application of Ernest Hopkinson, of New York, N. Y., for an improvement in Processes for Obtaining Rubber-Containing or Similar Materials, errors appear in the printed specification requiring correction as follows: Page 1, line 36, after the Word than insert the word that; page 3, line 10, for the word vulcanization read vuZcwnz'zi ng; same page, lines 58-69, claim3, strike out the words changing the fluid content of and insert the word drying instead; and that the said Letters Patent should be read with these corrections therein that the same ma conform to the record of the. case in the Patent Ofiice.

- Sign and sealed this 26th day of May, A. D. 1925 [snub] KARL FENNING,

Acting Commissioner of Patents.

Certificate of Correction.

It is hereby certified that in Letters Patent No. 1,526,984, granted February 1?, 1925, upon the application of Ernest Hopkinson, of New York, N. Y., for an improvement in Processes for Obtaining Ru'blxar-Containing or Similar Materials, errors appear in the printed specification requiring correction as follows: Page 1, line 36, after the word than insert the word that; page 3, line 10, for the word vulcanization read vulca-nz'zing; same page, lines 5&69, claim 3, strike out the words changing the fluid content of and insert the word drying instead; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 26th day of May, A. D. 1925.

[SEAL] KARL FENNING,

Acting Commissioner of Patents. 

